SoftBank in AI: Arm, Stargate and Its OpenAI Investment

From software distributor to holding company

Masayoshi Son founded SoftBank in September 1981 as a software distributor in Japan. It went public in 1994, and its defining early trade was a $20 million stake in a young Alibaba in 2000 that was worth tens of billions of dollars by the time Alibaba went public in 2014. SoftBank bought the British chip designer Arm for more than $32 billion in 2016 and still holds a controlling stake. In 2017 it launched the Vision Fund with Saudi Arabia's Public Investment Fund, at the time the largest private equity vehicle of its kind, built to make large, concentrated technology bets rather than a diversified portfolio. [2]

Atlas interpretation: That history matters for reading SoftBank's AI bets: this is not a fund built to hedge, it is a fund built around Son personally deciding a technology is the next one worth going all in on. AI is the current version of that bet, applied at the scale of data centers and chip supply rather than single company stakes. [2]

Committing to Stargate

In January 2025, SoftBank joined OpenAI, Oracle and MGX to announce the Stargate Project, a joint venture to build AI data center capacity in the United States with a stated $500 billion investment figure. The announcement named Son as chairman of the venture alongside OpenAI's Sam Altman and Oracle's Larry Ellison, putting SoftBank in the small group of companies treating AI compute capacity itself, rather than any single model or product, as the thing worth committing hundreds of billions of dollars to build. [3]

Selling Nvidia to pay for OpenAI

By late 2025 SoftBank had built a stake in OpenAI reported at roughly $34.6 billion, on top of its Stargate commitment. In November 2025, SoftBank disclosed it had sold its entire remaining Nvidia stake, 32.1 million shares, for $5.8 billion, in its October earnings presentation. Chief Financial Officer Yoshimitsu Goto stated the reason plainly: more than $30 billion needed to go into OpenAI that year, and SoftBank needed to divest existing holdings to raise it, with its total OpenAI investment for the year projected at $34.7 billion. [4][2]

Atlas interpretation: The sale is a concrete data point on how SoftBank is funding its AI position: not purely from fresh capital, but partly by liquidating one AI-adjacent holding, a chipmaker whose stock had risen alongside the AI buildout, to pay for a stake in the company whose demand for chips helped drive that rise in the first place. [4]